Target Generation Using Geospatial Data Integration at the Labrador Trough Zinc–Copper Project, Labrador–Quebec, Canada

2015

Elisabeth Ronacher (Ronacher McKenzie Geoscience), Jenna McKenzie (Ronacher McKenzie Geoscience), Roderick Smith (Callinan Royalties Corp.)

The Callinan Royalty Corp. Labrador Trough project is located in the southern part of the Labrador Trough in Labrador and Quebec, Canada, 50 km east of the community of Schefferville. The property covers more than 1,600 km2 and has been previously explored for sediment- and volcanic-hosted, base-metal (Zn–Cu) massive-sulfide deposits. Ronacher McKenzie Geoscience compiled and reviewed available geospatial and exploration data and completed a data analysis and interpretation with the goal of identifying economic concentrations of zinc and copper mineralization within the project area. The area of interest has been explored since the late 1930s, originally for iron ore, and a fair amount of historic exploration data is available from the provincial governments. The historic exploration and work by geological surveys identified numerous base-metal occurrences. Initially, the geospatial data comprising geological information (e.g., maps at various scales, mapped structures, drill hole data), historic reports, geochemical data (e.g., rock, lake bottom sediment, glacial till) and geophysical data (e.g., magnetic surveys) were compiled. This information was collected, reviewed and integrated on a GIS platform (ArcMap). In conjunction with the geospatial data compilation, a geophysical forward model was calculated by creating a tabular body in the Gocad® 3D modeling software to mimic the magnetic response of a buried massive-sulfide deposit and to determine if such a response was detectable in the available magnetic data. The body was then forward-modelled using the UBC-GIF MAG3D forward modelling and inversion code to produce the theoretical magnetic response of various locations, depths and magnetic susceptibility contrasts. The results showed that anomalies are detectable. The geospatial data analysis included determining favorable stratigraphic units, identifying geochemical anomalies, recognizing magnetic anomalies based on the forward model and completing a detailed structural analysis of the magnetic data. Historic exploration data were reviewed, ranked by significance for targeting and spatially integrated. Data analysis was followed by data interpretation: (1) the geochemical and geophysical anomalies were ranked and integrated with the geological and stratigraphic data, and (2) the structural features identified using the magnetic data were interpreted and classified genetically, and a time-sequence was proposed for their origin. The results of the data interpretation indicated that several mineral occurrences are spatially associated with the structures identified by the data analysis. The results allowed for efficient targeting and ranking of anomalies, and six high-priority areas for massive-sulfide base-metal mineralization were identified for follow-up exploration.

Mots Clés: base-metals, Labrador Trough, target generation, geologic data integration, integrated data analysis, geology, geospatial data analysis, geophysics